Insulating covering



Dec. 4, 1951 P. F. M DERMOTT ET AL INSULATING COVERING Original Filed Nov. 11, 1943 S R O T N E V W PAUL F. MCDERMOTT, DECEASED, BY MARY McDERMoTT,ADM|N|sTRATR|x,

AND' HARRY E. HOLCOMB Patented Dec. 4, 1951 INSULATING COVERING Paul F. McDermott, deceased, late of Martinsville, N.' J., by Mary McDermott, administratrix, Plainfield, N. 3., and Harry E. Holcomb, Stratford, Gonm, assignors to Johns-Manville Corporation, New York, N. Y., a corporation of New York Original application. November 11, 1943, Serial No. 509,880, non Patent No. 2,445,624, dated July 20, 1948; Divided and this application January 29, 1948, Serial No. 4,966

4 Claims. i

The present invention relates to insulating coverings for tubes, pipes, and the like and more particularly to seamless tubular coverings for such purposes. This application is a division of copending application, S. N. 509,880, filed Novemberll, 19.43, now. Patent Number 2,445,624, issued July 20, 1948.

Heretofore in the insulation of tubes, small pipes and assemblies thereof such as employed, for example, for certain aircraft fluid lines, it has been conventional to. wrap an insulating tape spirally around the line and the line fittings. The application of the insulating material by such operations is necessarily slow and laborious. Furthermore it is difficult to obtain and maintain that degree of tightness between adjacent spirals of the tape rec uiredhtov insure. uniform coverage over the entire area of the tube or line. A principal object of the invention is the provision of a seamless tubular pipe covering which may be drawn endwise over lines of considerable length, eliminating the necessity of spirally wrapping the covering material directly on the line. In a preferred embodiment the covering is of a character to yield to conform to fittings and sections of varying diameters.

A more specific objectof the invention in the preferred embodiment is the provision of a tubular insulating covering which is flexible and pliable, and capable of. being readily stretched or contracted to fit enlarged or smaller sections of the line.

Another object of the invention is the provision of a tubular, seamless covering comprising spiral windings of asbestos listing, roving, or other strand-like material, the windings being secured in contiguous relationship into a unitary, integrated bodyby anadhesive material.

A further object of the invention in the preferred embodiment thereof is the provision of a tubular covering asreferred to inwhich the adhesive material is of a flexible, extensible character.

The invention will be more fully understood and further objectsand advantages thereof will become'apparent"whnieference is made to the more detailed description which is to follow and to the accompanying drawings in which:

Fig. l is a perspective view of a tubular covering in accordance with the invention;

Fig. 2 is an elevational view illustrating the application of the tubular covering to a small diameter pipe line, or the like; and,

Fig. 3 is a perspective view illustrating a modified embodiment of the invention.

Referring now to the drawings and particularly 2 to Figs. 1 and 2, there is shown a seamless, tubular covering IF], particularly adapted for small pipe lines, and the like, or other similar equipment to be insulated or covered. However, the covering may be made in relatively large diameters for larger sized pipes, if desired. The covering in the preferred embodiment of the invention is made up of a plurality of strands I2 lying in parallel, contiguous spirals or windings to form a hollow, tubular structure, and an adhesive material it securing the strands together and maintaining them in assembled relationship.

The individual strands may be of any suitable type but are preferably composed of asbestos fibers with or without the addition of other fibers,

reinforcing threads, and the like. They maybe in the form of ropes, rovings, wickings, listings, and similar strand materials, and are of a diameter determined by the thickness desired for the walls of the covering. The number of individual strands making up the covering may be varied, as desired, to adjust the slope or pitch of the spirals and thereby vary the relative longitudinal and circumferential yieldability of the covering, as will be hereinafter more fully pointed out.

The adhesive, which may be used either as a strand impregnant or as a coating on the assembly, preferably the latter, may vary from a material which, when set or dried, is relatively unyie dable and rigid, to one which is yieldable and extensible, depending upon the particular use to which the coverin is to be put. In the preferred embodiment of the invention the adhesive is applied as a coating after assembly of the strands into tubular form, and is of a yieldable, extensible character which will permit the tube to be stretched, both circumferentially and longitudinally.

In forming the covering the strands are wrappedby suitable winding apparatus in contiguous spirals around a carrying element supported by a mandrel or the like, the carrying element being moved longitudinally. of the mandrel to carry the assembly of wrapped strands away from the wrapping point without separation of the windings, as fully described in said copending application, S. N. 509,880. The coating is applied and set while the strands are supported on the carrying element, the carrying element then being removed or its non-extensible characteristics eliminated whereby the covering can exhibit the properties of extensibility and contractability referred to above.

As pointed out above, one use of the instant 56 product of special importance is in covering relatively small oil lines, and the like, such lines being of considerable length and often .including portions of enlarged diameters. A line of this chartaining the strands in assembled relationship.

may be readily applied by forcing it endwise onto the line. Due to the fact'that the covering is formed solely of the spiral windings, and the yieldable coating, its diameter may be varied as necessary,to conform to enlarged portions or fittings, change in diameter causing a related change in the pitch of the spiral windings. It will be appreciated that increase in diameter of the covering is caused by endwise compression, while the reduction of diameter is caused by endwise stretching. In applying the covering to a line as illustrated in Fig. 2, forcing of the covering onto the enlarged portion causes the covering toexpand in diameter. After the section is applied, endwise stretching causes diameter reduction until the covering closely embraces the line at all points. The covering may be supplied in slightly oversized diameter so that it is easily applied to relativelylong lengths of thellne and then, by longitudinal stretching, brought into close fitting contact throughout. The relative circumferential and longitudinal stretch characteristics are primarily dependent upon the pitch of the spirals which in turn depends upon the number and size of the individual strands employed for a given diameter of the covering. For purposes of example and without limiting the invention, it may be stated that coverings particularly suitable for the purposes referred to above, andof nominally 4" inside diameter, have been made of from 1 to 18 strands of asbestos wicking, each approximately in diameter. From 1 to22 strands and from 1 to 30 strands have been employed, respectively, to produce coverings of 1" and 1 nominal inside diameters.

Suitable adhesive coatings or impregnants for securing the spiral wrappings in their contiguous relationship are bitumens, rubbers, glues, sodium silicate, natural or synthetic gums, natural or synthetic resins, and other glues and pastes, the particular adhesive material, as previously explained, depending upon the desired properties of the completed covering. For the yieldable, extensible covering referred to above, a vinyl resin has been found to be particularly satisfactory. The adhesive is preferably applied in the form of a coating to the exterior of the strands but, as

has been indicated, the individual strands may be previously impregnated with an adhesive in an unset condition, and the adhesive set after assembly of the strands. Also, combinations of impregnants and coatings may be employed. In the event an adhesive or coating is used which is relatively rigid or hard when set, the tube may be bent to various shapes or otherwise distorted before setting of the adhesive to obtain a product molded to the desired design.

. If desired, the individual strands may be reinforced as, for example, by an inserted reinforcing core or element 18, as indicated in Fig. 3. Also, a plurality oflayers or windings 20 and 22 of strands of the same or different diameters may be used, as indicated in Fig. 3.

A product in accordance with the instant invention and as described above fully attains the objects of the invention as set forth above. The covering may be easily and quickly applied to the line to be covered and will closely conform to the variations in shapes and sizes of the line. Due to the simplicity of the construction the covering is relatively inexpensive to manufacture.

Having thus described the invention in rather full detail, it will be understood that these details need not be strictly adhered to and that various changes and modifications may suggest themselves to one skilled in the art, all falling within the scope of the invention as defined by the subioined claims.

What we claim is:

1. A flexible product consisting of successive windings of strand material defining a hollow tubular member, and a layer of flexible, extensible adhesive material covering the outer face of said tubular member, and securing said windings in tube depening relationship to form a substantially unitary structure.

2. A covering consisting of a plurality of strands wound in parallel, continuous spirals to form a hollow tubular member, and a flexible, extensible adhesive material securing said strands together in tube defining relationship.

3. An insulating covering consisting of a plurality of asbestos strands having reinforcing elements, said strands being wound in continuous, contiguous spirals to form a hollow tubular member, and a flexible, extensible adhesive material securing said strands in assembled, tube defining relationship.

4. A tubularinsulating covering consisting of a plurality of'layers of strands wound in contiguous spirals to form a hollow tubular member, and a flexible, extensible adhesive material securing the strands of the outer layer together in tube defining relationship.

7 MARY MCDERMOTT, Administratrix of the Estate of Paul F. McDermott, Deceased.

HARRY E. HOLCOMB.

REFERENCES CITED The following references are of record in the leof this patent:

UNITED STATES PATENTS Number Y Name Date 529,412 Robinson Nov. 20, 1894 1,895,400 Reeves Jan. 24, 1933 2,094,919 Hughes Oct. 5, 1937 2,120,885 Chatterton June 14, 1938 2,315,837 Brown et al. Apr. 6, 1943 2,370,046 Keyes Feb. 20, 1945 

